Which is an example of encryption in transit?

• A. Encrypting backups at rest.
• B. Encrypting email content at rest.
• C. Full-disk encryption protecting stored data.
• D. TLS or IPsec protecting data moving across networks.

Answer: (D)

Data in transit refers to information traveling over networks. Encryption in transit means the data is encrypted while it’s being transmitted, so it remains confidential even if someone intercepts the traffic. Using TLS or IPsec to protect data moving across networks creates an encrypted channel between endpoints, ensuring that the payload cannot be read or tampered with during transmission. In contrast, encryption at rest protects data when it’s stored—backups stored on disk, email content saved on servers, or full-disk encryption—so those do not illustrate encryption in transit. Therefore, the mechanism that exemplifies encryption in transit is the use of TLS or IPsec to protect data as it moves across networks.